Climatic extremes improve predictions of spatial patterns of tree species

By: , and 



Understanding niche evolution, dynamics, and the response of species to climate change requires knowledge of the determinants of the environmental niche and species range limits. Mean values of climatic variables are often used in such analyses. In contrast, the increasing frequency of climate extremes suggests the importance of understanding their additional influence on range limits. Here, we assess how measures representing climate extremes (i.e., interannual variability in climate parameters) explain and predict spatial patterns of 11 tree species in Switzerland. We find clear, although comparably small, improvement (+20% in adjusted D2, +8% and +3% in cross-validated True Skill Statistic and area under the receiver operating characteristics curve values) in models that use measures of extremes in addition to means. The primary effect of including information on climate extremes is a correction of local overprediction and underprediction. Our results demonstrate that measures of climate extremes are important for understanding the climatic limits of tree species and assessing species niche characteristics. The inclusion of climate variability likely will improve models of species range limits under future conditions, where changes in mean climate and increased variability are expected.
Publication type Conference Paper
Publication Subtype Conference Paper
Title Climatic extremes improve predictions of spatial patterns of tree species
DOI 10.1073/pnas.0901643106
Volume 106
Issue SUPPL. 2
Year Published 2009
Language English
Larger Work Title Proceedings of the National Academy of Sciences of the United States of America
First page 19723
Last page 19728
Google Analytic Metrics Metrics page
Additional publication details